This invention relates to a static relay for low DC-voltages to be supplied to a load. The relay comprises a bipolar output transistor of a first conductivity type whose emitter is connected to an output terminal to which the load is to be connected. The load is further connected to a common supply terminal. The collector of the transistor is connected to a main supply terminal, and the base of this transistor is fed through the main current path of a current injection transistor, which has a control electrode which, when it is operated via a control terminal, causes this transistor and also the bipolar output transistor to become conductive.
Such a static relay can be utilized in the field of electrical equipment for automobiles, in which application it replaces advantageously the conventional systems comprising electromagnetic relays.
French Patent Application No. 2,524,711 filed by "General Electric Company-US" and published on Oct. 7th 1983 discloses a static relay of the aforementioned type.
Such a relay is not adapted to use in electrical equipment for automobiles, for which the various bulbs have to be fed by control transistors at the nominal voltage of the battery and for which the circuit has to permit the identification of anomalies relative to the load, i.e. non-connection of shortcircuiting of this load. According to preferred embodiments the relay should also provide protection from anomalies relative to the electric supply of the relay.